Some major intermediates derived from formaldehyde are chelating agents, acetal resins, 1,4-butanediol, polyols, methylene diisocynate. It is also used for the manufacture of wide variety of chemicals, including sealant, herbicides, fertilisers, coating, and pharmaceutical. Product profile of formaldehyde is given in Table M-VII 4.7.
Formaldehyde is commercially available as aqueous solution with concentration ranging from 30-56 wt.% HCHO. It is also sold in solid form as paraformaldehyde or trioxane. The production of formaldehyde in India has been growing at a fairly constant rate during last ten years. There are presently about 17 units in India. Installed capacity and production of formaldehyde during 2003-04 was 2.72 lakh tonnes and 1.89 lakh tonnes respectively.
Various industrial processes for manufacture of formaldehyde using silver and ironmolybdenum catalyst are given below:
Catalyst Process licensor
Silver catalyst processes Bayer, Chemical construction, Ciba, DuPont, IG Farben, CdF Chemie process, BASF process, ICI process,
Iron-molybdenum catalyst processes Degussa process, Formox process, Fischer-Adler, Hiag-Lurgi, IFP-CdF Chimle Lumus, Motedisous, Nikka Topsoe, Prolex
Process diagram for manufacture of formaldehyde using silver and iron-molybdenum catalyst is shown in Figure M-VII 4.5 and Figure M-VII 4.6 respectively.
Table M-VII 4.7: Product Profile of Formaldehyde
Thermosetting resin: Phenol, Urea Melamine, Formaldehyde resins
Hexamethylenetetramine, Plastic & pharmaceuticals
Fertiliser, Disinfectant, Biocide Preservative, Reducing agent, Corrosion inhibitor
Polyaceta resin p-formaldehyde
Pentaerythritol (Explosive-PETN),Alkyl resins
Table M-VII 4.8: World Acetic Acid Capacity and Consumption Pattern
Capacity due by 2012 (’000 tonnes)
Capacity Change Needed by 2012 2002 after Announcement
Table M-VII 4.9: Installed Capacities of Acetic Acid in India
Installed capacity (TPA)
Indian Organics Chemicals Ltd.
Somaiya Chemicals ltd.
Andhra Sugars Ltd.
Ashok Organic Industries
EID Parry (I) Ltd.
Gujarat Narmada Valley Fertiliser Corp. Ltd.
Kanoria Chemicals & Industries
Laxmi Organic Ltd.
Ashok Alcochem Ltd.
Dhampur Sugar mills
Table M-VII 4.10:Market Share of Major Acetic Acid Manufacturer
Name of the companies
Jubilant Organosys Ltd.
Ashok Organics ltd.
Gujarat Narmada Valley Fertiliser Corp. Ltd.
Table M-VII 4.11: Product Profile of Acetic Acid
Mono chloro acetic acid
CMC manufacture, adhesives, thickeners for drilling muds, food industry, pharmaceuticals, textiles, 2,4-D(insecticides)
Ethyl acetate,n-butyl acetate, isopropyl acetate
Coatings, adhesives, inks and cosmetics
Fibers, plastic film
Pharmaceuticals, intermediates, cellulose acetate
Pharmaceutical, dyes intermediate, Rubber accelerator, Peroxide stabilizers
Per acetic acid
Terephthalic Acid, DMT
Polyester fiber, packaging, photographic films, magnetic tape sectors
Polyvinyl acetate, polyvinyl chloride, paints, Adhesives, and coatings
Chloromethanes (Methyl Chloride, Methylene Dichloride, Chloroform, Carbon Tetrachloride)
Chlorinated methanes, which include methyl chloride, methylene dichloride, chloroform and carbon tetrachloride, are important derivatives of methane and find wide application as solvents and as intermediate products. Product profile of Chloromethane is given in Table M-VII 4.12
Table M-VII 4.12: Product Profile of Chloromethane
Refrigerant, butyl rubber, silicones, solvent, tetramethyl lead, intermediates
Solvent, Intermediates, Photographic film, Degreasing solvents, Aerosol, Propellants
Chlorodifluoro methane, (Refrigerants), Propellants,
Dichlorodifluoro methane, Trichlorofluoro methane, Solvent, Fire extinguishers
There are two major routes for the manufacture of chloromethane:
Direct Chlorination of Methane: Chlorination of methane (natural gas) is carried out at around 400-450 oC during which following reaction takes place:
Dimethyl Formamide [Hcon(Ch3)2]
Dimethyl formamide is one of widely used solvents in the manufacture of acrylic fiber. Because of its high dielectric constant, aprotic nature, wide liquid range and low volatility, dissolving power it is frequently used for as solvent.
Dimethyl formamide is made by following two processes:
Two step process
Process involves carbonisation of methanol to methyl formate using basic catalyst and reaction of methyl formate with dimethylamine.
It plays important role during and after World War II in providing feedstock for large number of organic chemicals when petrochemical industry was not well developed. Acetylene’s highly reactive triple bond provided a ready “handle” for chemists to grab onto for designing process chemistry Safety issues involved with handling of large volumes of acetylene and its expense are big problem with adoption of acetylene based processes. The process of acetylene requires much energy and is very expensive. of attractive petrochemical feedstock. Acetylene is still being used for manufacture of chemicals.
Various Routes for Acetylene:
Calcium Carbide Route: This is the oldest method for production of acetylene and still acetylene is produced by this process in small scale as well large scale. Calcium carbide is produced by reacting lime with coke at temperature 2,000-2,100 oCin an electric furnace. Two processes produce acetylene from calcium carbide process: Wet process and Dry process. Dry process is preferred as in case of calcium hydroxide, which is produced during the process (is produced in the form of dry calcium hydrate).
CaC2 +2 H2O→ C2H2 + Ca(OH)2
Acetylene from Cracking of Hydrocarbons: Cracking of hydrocarbons such as methane, ethane, propane, butane, ethylene, and natural gas can make acetylene.
Product Derived from Acetylene: Acetylene is extremely reactive hydrocarbon and was initially was used for the manufacture of large number of chemicals which are now being derived from acetylene route. Product profile of acetylene is given in Figure M-VII 4.7 and Figure M-VII 4.8
Figure M-VII 4.7: Product Profile of Acetylene
Acrylonitrile: HC≡CH+HCN → HC=CH= CH2=CHCN
HC≡CH+CH3COOH → CH2 = CHOOCCH3
HC≡CH+CH3COOH CH2 = CHOOCCH3
CH2 = CHOOCCH3+Cl2 CH2=CClCH=CH2
Vinyl Chloride and Vinylidene Chloride
HC≡CH+HCl → CH2 =CHCl
CH2 =CHCl+Cl2 → CH2 ClCHCl2
CH2 ClCHCl2 → CH2 = CCl2+ HCl
HC≡CH+ HF → CH2=CHF
Figure M-VII 4.8: Reactions in Acetylene derived Chemicals